I searched but didn't really come up with what I am looking for.
I just ran the pex lines and popped in the room (basement) where the hot air furnace is and my water heater.
My plan is to put a heat exchaner in the plenum, use a side arm exchanger for the domestic HW and I am going to install a small air to water exchanger through the wall with a blower behind it kind of like a Modine unit.
I have 1 1/4" Pex, I read somewhere that I can loop the supply and return and put Tee's in wher I need them for the appliances. I have seen some info on just doing the side arm first, then the water to air in the plenum in series. Which way makes the most sense?
Happy burning :)
Thanks in advance
When I did mine I went to the furnace first and then back thru the plate exchanger for the water heater. It has been that way for 15 years now and have never run out of hot water
Altho it'll work hooked up in various orders, I always do domestic water first, then forced air. That way you will have even temps for domestic water when the house heat is kicking on and off. But I use a flat plate rather than a side arm.
If I understand your question you are asking if placing your various heat exchangers in parallel vs in series will work? If so the answer is it depends. The issue with parallel connections is the flow will always take the easiest path when given a choice which may not be necessarily where you want it to go. The issue if you install everything in series is each exchanger must be able to handle the total system flow. My system is in series with the domestic being first in line as most recommend. Yes it is possible to add a loop in parallel to a system set up in series, how well it works depends on the working head of each. A friend added an upstairs room heater in parallel to his series loop system and it didn't work at all, I added a ball valve just after his tee in the feed line which served as an adjustable choke in the loop which in turn forced a portion of the flow to go to his room heater. We adjusted the valve to suit the needs of the heater It worked but probably not by the book.
Mine goes to the water heater first and then into the furnace. also put in a line and valves to bypass the furnace in warm weather when you only want to heat the water.
Thanks for the info.
I have one other question, is it OK for the pipes coming in to go up and over to the domestic then back up and over to the furnace? Otherwise the pipes will be at chest height in my way to service the oil burner.
My experience has been that if the pump is out at the furnace where it belongs that it will shove the air out of the lines. Thus you can run them however manner works best for you.
Looping up to the ceiling should be no issue. I always plumb a fill valve in at the water heater to purge the air out with house water pressure. With no air it balances, just as much water falling as is rising, so it flows fine.
I have a short water heater due to the space I have, I put a side arm on it a couple years ago, seems to be a waste of money, it didn't work at all. Granted I could not have the sidearm straight up and down due to the height of my water heater constraints. I have it connected to the bottom of the heater, and the top of the heater just as i should. Paid good money for that sidearm too. but like i said didnt work at all.
A flat plate would probably work better in your situation.
Mind is run to the furnace first then to the hot water heater. I run a flat plate on the hot water heater. I have a thermostat that turns on the Garn pump and a pump on the domestic side of the flat plate when the water needs heat. Work's real good and never run out of hot water as long as the Garn has heat in it. I heat my domestic year around with wood.
Would be neat to see some pics of that setup.
So I now have a new dilemma, sort of. It looks like I'm going to have to size down to 1" pex from where the pex enters the room. Our local supplier FW Webb doesn't have 1 1/4" Pex nor can they get it. At least that's what they told me. I can mail order some but it's just not cost effective. I don't really see this as a big problem as I was originally going to run 1" the entire way. I like the idea of a plate exchanger at the water heater instead of a sidearm.
Edit: I want to add a fresh water fill to the return line, I will use a ball valve, my question is should I have a flow check in the return line or won't it matter? FYI my system is an open system. It's a Heatmor 200ss
Quote from: Logging logginglogging on September 17, 2019, 11:00:55 AM
Would be neat to see some pics of that setup.
Sorry I am pretty low tech and don't have a way to post pictures. Gave up my smart phone when I took early retirement a couple years ago.
Dave
I guess I wouldn't worry about going to one inch as the heat exchanger you are putting in your furnace is probably one inch. Flat plates can be bought either way. I have two loops on my Garn that are 450 feet each and are one inch and have no problems with flow. A back flow check could be used were the domestic is going to hook up to make sure you don't get any boiler water in your domestic water. Most boiler systems don't have enough pressure to over come the domestic water pressure.
Dave I'm not sure where you are but I have a partial roll of 1-1/2 pex in Barnet Vt.
I appreciate it but I think I'm set now. I am about 4 miles from the VT border outside of Arlington VT into NY.
I see I had a typo in that above reply, should have read 1 1/4 not 1 1/2, I fixed it.
A little updating, I received my 18x20 HX, a 10 plate HX for the domestic and a Taco 009.
I found out that the bladder in the stove is all dry rotted and needed to be replaced, luckily I found them on sale for $35.
I got the 1 1/4 to 1 reducers in, one flange for the pump in, I sweat the adapters on to the big HX (fingers crossed as I haven't done any soldering in years)
I mounted a board to the wall to attach the pipes to, and then I installed a junction box with an outlet in it, I'm going to put a cord on the pump so it will plug in.
One sucky thing I am dreading is the HW tank is plumbed with cpvc piping. Someday I would like to change the house to all Pex.
Well it's all plumbed up and full and so far no leaks!
I sort of changed things on the fly, I went to the HX in the plenum first, then to the HX in the wall and finally to the plate HX then to the return.
The reason was it just made sense as this was kind of the natural order of the route.
I'm excited to fire it up but I have to finish the wiring , the HX in the wall has a two speed blower on it and will be on a thermostat to help keep the finished basement warmish.
I'll probably hold off firing it until the weekend when I can be around all day to keep an eye on things.
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My home brewed HX for in the wall, this HX is 18" x 10" tall and 5" thick, I built the box and built it into the wall, I'll have to find a vent cover for it.
The wall side
Well I can't seem to attach photos so you'll just have to take my word for it! LOL
Update 10/26/19
Fire has been lit 8)
I have some "free" heat coming into my basement smiley_clapping
I do have a bit of learning to do, the unit got up to about 175 ish and the draft inducer kicked off. That was about 2.5 hrs ago. I'm trying to figure out how to get the inducer to come back on?
Anyway it feels good that I have water moving through the appliances :)
I still need to get a fan control board to trigger the blower in the furnace. I'll order it now and have it hear on Tuesday.